1. Field of the Invention
This invention relates to hose couplings, and in particular to a safety disconnect high pressure coupling which features a dual detent structure which produces an audible warning of a high pressure line condition while simultaneously bleeding off the high pressure line prior to complete disconnection of the coupling halves.
2. Description of the Prior Art
In a number of important industrial applications, high pressure conduits are connected together by a suitable coupling, such as a quick connect coupling, to carry fluids under pressure from a high pressure source to a load. A typical application involves the use of compressed air as a source of energy for actuating a portable hand tool. In such an arrangement compressed air is delivered from a compressor through a flexible hose to the portable tool. The flexible hose is usually furnished in sections of various lengths, with the sections being coupled together by means of fittings or couplings. Additionally, the hose couplings are sometimes attached to a manifold member.
Because the compressed air line operates at relatively high pressures, for example at pressure levels in the range of 90 psi to 150 psi, if the coupling becomes accidentally disconnected, the hose line will be propelled by the compressed air as it escapes and will cause the hose to whip around in an uncontrollable manner which can cause serious personal injury.
A large number of accidents involving personal injury are caused by disconnecting a high pressure coupling without first bleeding off the line. High pressure hose lines are relatively heavy and unwieldly even when unpressurized so that it is sometimes difficult for an operator to determine if a line is pressurized. The line may be pressurized to a dangerous level even though the compressor to which it is connected is not operating. Therefore the disconnection of a hose coupling on a high pressure line can expose the operator or his co-workers to the risk of serious personal injury if the line is disconnected without first bleeding off or otherwise its pressure. Because high pressure lines are sometimes handled by inexperienced operators, and are sometimes stiff or relatively inflexible so that even an experienced operator cannot determine in advance whether or not the line is pressurized, and because of the serious risk of personal injury associated with the inadvertent or improper disconnection of a high pressure line, there is a continuing interest in improving high pressure hose couplings so that disconnection of a high pressure line can be carried out safely and quickly even by an inexperienced operator.